PLOD1 and Hypergonadotropic hypogonadism: MH can occur due to an intrinsic defect of the testes (primary hypogonadism), in which the Leydig, Sertoli, and germ cells are impaired, or at the level of the hypothalamus or pituitary gland (secondary hypogonadism), in which the testes lack gonadotropic stimulation by luteinizing hormone (LH) and follicle-stimulating hormone (FSH) [1].